Numerical study of turbulent boundary-layer flow induced by a sphere above a flat plate

Abstract

The flow past a three-dimensional obstacle on a flat plate is one of the key problems in the boundary-layer flows, which shows a significant value in industry applications. A direct numerical study of flow past a sphere above a flat plate is investigated. The immersed boundary (IB) method with multiple-direct forcing scheme is used to couple the solid sphere with fluid. The detail information of flow field and vortex structure is obtained. The velocity and pressure distributions are illuminated, and the recirculation region with the length of which is twice as much as the sphere diameter is observed in the downstream of the sphere. The effects of the sphere on the boundary layer are also explored, including the velocity defect, the turbulence intensity and the Reynolds stresses.